A method to develop a model system for nonradioactive DNA hybridization/detection for identification of bacteria will be developed. DNA for ampicillin resistance (ampr) will be labeled with biotinylated deoxyuridine triphosphate by nick translation and used as probe. Colony hybridization procedures for the detection of ampr in E. coli will then be developed. Detection of hybridized biotinylated DNA will be done by detection of biotin by streptavidin, a biotin binding protein linked to a color producing enzyme. Once the system is established, attempts will be made to detect sequences of lower copy number and of shorter length. Attempts will be made to shorten the time required to perform the procedure. This model system is being developed as a basis for adaptation to direct (non-growth) tests for bacterial pathogen-containing clinical samples. Potential commercial significance that could be realized from development of this technology is fast and convenient diagnosis and characterization of bacterial infections.